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Taxon  Report  
Calochortus tiburonensis  A. J. Hill
Tiburon mariposa lily
Calochortus tiburonensis is a perennial herb (bulb) that is native to California, and endemic (limited) to California.
California Rare Plant Rank: 1B.1 (rare, threatened, or endangered in CA and elsewhere).
State of California status: Threatened. Federal status: Threatened.
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Observation Search
~69 records in California
yellowone or more occurrences
within a 7.5-minute quadrangle
DJJJASONAFMM

Bloom Period
Genus: Calochortus
Family: Liliaceae  
Category: angiosperm  
PLANTS group:Monocot
Jepson eFlora section: monocot

Ultramafic affinity: 6 - strict endemic

Communities: Valley Grassland

Name Status:
Accepted by JEF + CNPS + PLANTS

Information about  Calochortus tiburonensis from other sources
Nursery availability from CNPLX
Commercial availability unknown.
Jepson eFlora

USDA PLANTS Profile (CATI3)

Photos on Calflora

Photos on CalPhotos

Google Images

Photos on iNaturalist

ID Tips on PlantID.net

[Wikipedia] Description, Conservation, Rarity: Calochortus tiburonensis, the Tiburon Mariposa lily, is a rare member of the genus Calochortus in the family Liliaceae. It is endemic to Marin County, California, where it is known only from one population on Ring Mountain east of Mill Valley. There it occurs on a single serpentine outcrop in grasslands from 50?150 metres (160?490 ft) in elevation.[2][3] Conservation The plant was federally listed as a threatened species in 1995. It is considered threatened due to loss of surrounding habitat to recreational activities, to competition from invasive plant species, to its proximity to a dense population center, and to its confinement to a single population of plants. The population grows on land owned by the Marin County Open Space District,[7] an area previously owned and preserved by The Nature Conservancy.[6] It was first brought to the attention of science in 1971, and was described to science in 1973.[8] It is protected along with a number of other rare serpentine soils endemic plants that grow on and around Ring Mountain.[6][5] The plant has probably always been rare and limited to its current distribution on the Ring Mountain outcrop.[6] A 1991 estimate placed the total population size at about 40,000 individuals.[6][1] While the land is protected, the flora upon it are still vulnerable to events such as wildfires or drought, and to damage from off-leash dogs, hikers, cyclists, vandals, and wildflower collectors.[6] (contributed by Mary Ann Machi)


Suggested Citation
Calflora: Information on California plants for education, research and conservation, with data contributed by public and private institutions and individuals. [web application]. 2024. Berkeley, California: The Calflora Database [a non-profit organization]. Available: https://www.calflora.org/   (Accessed: 04/22/2024).